/*
 * Copyright (C) 2014 Lucid Wolf
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.lucidhex.util;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Set;

/**
 *
 * @author Wolf
 */
public class DualMap<A,B> {
    private HashMap<A,B> aTb = new HashMap<>();
    private HashMap<B,A> bTa = new HashMap<>();
    
    public B get(Object a){
        return aTb.get(a);
    }
    public A reverseGet(Object b){
        return bTa.get(b);
    }
    public ArrayList<Object[]> put(A a, B b){
        ArrayList<Object[]> out = null;
        B oldB = aTb.put(a,b);
        A oldA = bTa.put(b, a);
        if(oldA != null){
            aTb.remove(oldA);
        }
        if(oldB != null){
            bTa.remove(oldB);
        }
        if(oldA != null && oldB != null){
            
        }else{
            out = new ArrayList<>(2);
            out.add(new Object[]{a, oldB});
            out.add(new Object[]{b, oldA});
        }
        return out;
    }

    public Set<A> getKeySet() {
        return aTb.keySet();
    }

    public Set<B> getValues() {
        return bTa.keySet();
    }

    public boolean isEmpty() {
        return aTb.isEmpty();
    }

    public void clear() {
        aTb.clear();
        bTa.clear();
    }

    public void remove(A a) {
        B b = aTb.remove(a);
        bTa.remove(b);
    }
}
